Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From silicon reactant having at least one...
Reexamination Certificate
2002-04-25
2004-06-01
Peng, Kuo-Liang (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From silicon reactant having at least one...
C528S043000, C528S032000, C568S001000, C502S202000, C106S035000, C526S279000, C549S215000
Reexamination Certificate
active
06743883
ABSTRACT:
The present invention relates to the field of initiation of reactions for polymerising and/or cross-linking polyorganosiloxane-type monomers, oligomers and/or polymers containing reactive functional radicals capable of forming intra- and inter-catenary bridges so as to obtain a corresponding matrix.
More particularly, its main aim is to provide new initiators which will lead to these matrices.
This type of matrix is of particular interest for the preparation of multiple compositions such as dental materials, adhesives, sealants, jointing products and adhesive finishes.
The applications targeted more particularly by the invention are the use of compositions for the preparation of dental compositions such as dental prostheses or dental restoration materials and of compositions of the non-adhesive coating type used, in particular, to produce coatings on objects such as solid articles or substrates, in particular paper substrate, fabric, polyester or polyolefin type polymer film, aluminium substrate and/or metal substrate such as tin plate.
More precisely, the present invention relates to new initiators containing at least one boron derivative for the initiation and progress of resin or polymer forming reactions, starting from substrate derived from polyorganosiloxane-type monomers, oligomers and/or polymers with reactive organofunctional groups.
The reactions more particularly concerned are those in which agents act as direct promoters of the inter- and/or intra-catonary bonds In the present case, these reactions are initiated by heat activation.
In the present description, the resins and polymers obtained are prepared from polyorganosiloxane-type monomers, oligomers and/or polymers and contain, in their structure, organofunctional groups, for example of the epoxide, oxetane, dioxolane and/or alkenylether type, which react after activation of the initiators according to the invention described hereinafter. In addition organic monomers, oligomers and/or polymers which may be added to the polymerisation medium containing the aforementioned species may also be used.
The present invention also relates to compositions containing the basic materials such as cross-linkable polyorganosiloxane-type monomers, oligomers and/or polymers, the initiators described hereinafter and optionally one or more additives selected from those generally known in the applications for which these compositions are intended.
The initiators generally used to initiate the formation of resins or polymers on the basis of the aforementioned polymerisation and/or cross-linking of organosiloxane substrates may be divided into three categories, depending on their mode of activation. This mode of activation may in fact be thermal, photochemical or by an electron beam.
Conventionally, the initiator used, which is generally a cationic photoinitiator, releases a strong acid under irradiation during photochemical cross-linking such as UV radiation This strong acid catalyses the cationic polymerisation reaction of the functional groups. Initiators of this type are described, in particular, in EP-0 562 897. The initiating salts in that patent represent significant technical progress over the formerly known initiators of the onium salt or organometallic complex type, and in particular over those of which the anion of the initiating salt is SbF
6
— which is one of the only ones which has the correct performance but which poses serious problems infuse owing to the presence of heavy metals.
Thermal cross-linking, for its part, necessitates very high temperatures generally higher than 150° C. to trigger cross-linking. This second type of initiator is used, in particular, to cross-link silicones such as those described hereinafter (S1 to S15) in a thin layer and for epoxide or oxetanes.
One of the main aims of the present invention is specifically to propose new heat-activated initiators for triggering the cross-linking of polyorganosiloxane-type monomers, oligomers and/or polymers with functional groups at a temperature lower than 150° C. and preferably lower than 100° C., or even substantially at ambient temperature.
More particularly, the present invention relates firstly to a heat-activated initiator for polymerising and/or cross-linking monomers, oligomers and/or polymers with organofunctional groups, comprising a boron derivative of formula (I)
(A)
x
B(R′)
y
(I)
wherein
the symbols R′ are the same or different and represent
a linear or branched C
1
-C
12
, preferably C
1
-C
8
alkyl or alkenyl radical, optionally substituted by at least one electron-withdrawing element, in particular a halogen atom (more particularly fluorine) or an electron-withdrawing group, for example the CF
3
, NO
2
, CN groups,
a linear or branched C
1
-C
12
, preferably C
1
-C
8
alkoxy radical, optionally substituted by at least one electron-withdrawing element, in particular a halogen atom (more particularly fluorine) or an electron-withdrawing group, for example the CF
3
, NO
2
, CN groups,
a phenyl radical substituted by at least one electron-withdrawing element, in particular a halogen atom (more particularly fluorine) or an electron-withdrawing group, for example the CF
3
, NO
2
, CN groups,
an aryl radical containing at least two aromatic rings such as biphenyl, naphthyl, optionally substituted by at least one electron-withdrawing element, in particular a halogen atom (more particularly fluorine) or an electron-withdrawing group, for example the CF
3
, NO
2
, CN groups,
a —C
2
H
4
—Si(Q)
3
radical with the symbols Q being the same or different as representing a C
1
to C
10
alkyl or alkoxy group or a siloxane oligomer with less than 10 silicone atoms, substituted, if necessary, by a radical of formula B(R′)
2
with R′ as defined above or
two R′ groups may be bound to one another so as to form, with the boron atom to which they are bound, a cycle containing 5 or 10 atoms wherein said cycle may be saturated, unsaturated, bridged or aromatic and may comprise one or more heteroatoms selected from oxygen, nitrogen and boron atoms, wherein the boron atom present in said cycle may itself be substituted by a radical as defined for A or R′ in general formula I,
the symbols A are independent of one another and represent:
a hydrogen atom
a halogen atom or
a hydroxyl radical,
x represents 0 or the integer 1 or 2 and y represents an integer 1, 2 or 3 wherein the sum of x+y is equal to 3 and its solvated forms.
The initiators according to the invention are generally very hygroscopic compounds. Consequently, these compounds may be found in the form of a mixture between the compound as defined in general formula I and its various hydrated form(s). Similarly, when this initiator is formulated with a solvent, the formation of solvated derivatives is observed. This phenomenon can be observed with aprotic solvents such as ethers, esters and silicones or protic solvents such as alcohols, carboxylic acids, silanols, amines, thiols, water or mixtures thereof.
Consequently, the present invention also extends to these solvated forms.
The new initiators are of particular interest in terms of reactivity insofar as they are active at low concentrations and advantageously necessitate only small amounts of energy to carry out cross-linking. In fact, they may be activated at a temperature lower than 150° C., preferably lower than 100° C., or even at ambient temperature.
The initiators according to the invention may also be associated with a conventional initiator such as a cationic photoinitiator. This is particularly advantageous in terms of profitability insofar as it is thus possible significantly to reduce the effective quantity of conventional initiator. Furthermore, cross-linking and/or polymerisation are totally completed.
It has accordingly been found that the claimed initiators are particularly advantageous in terms of profitability and cost for industrial processes.
More preferably, the symbols R′ of general formula (I) are selected so as to give the boron atom to which they are bound adequate ste
Deforth Thomas
Frances Jean-Marc
Burns Doane Swecker & Mathis L.L.P.
Peng Kuo-Liang
Rhodia Chimie
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